Enter the body weight and daily requirement of magnesium into the calculator to determine the magnesium repletion. This calculator can also evaluate any of the variables given the others are known.

Magnesium Repletion Formula

The following formula is used to calculate the magnesium repletion.

MR = (BW * DR) / (SR * T)


  • MR is the magnesium repletion (mg) BW is the body weight (kg) DR is the daily requirement of magnesium (mg/kg) SR is the serum magnesium level (mg/dL) T is the target serum magnesium level (mg/dL)

To calculate the magnesium repletion, multiply the body weight by the daily requirement of magnesium. Then divide the result by the product of the serum magnesium level and the target serum magnesium level.

What is a Magnesium Repletion?

Magnesium repletion is a medical treatment process that involves the restoration of magnesium levels in the body when they are significantly low. This condition, known as hypomagnesemia, can lead to various health problems such as muscle weakness, seizures, and irregular heartbeat. The repletion process typically involves oral or intravenous administration of magnesium supplements under the supervision of a healthcare professional.

How to Calculate Magnesium Repletion?

The following steps outline how to calculate the Magnesium Repletion using the given formula:

  1. First, determine the body weight (BW) in kilograms (kg).
  2. Next, determine the daily requirement of magnesium (DR) in milligrams per kilogram (mg/kg).
  3. Next, determine the serum magnesium level (SR) in milligrams per deciliter (mg/dL).
  4. Next, determine the target serum magnesium level (T) in milligrams per deciliter (mg/dL).
  5. Finally, use the formula MR = (BW * DR) / (SR * T) to calculate the Magnesium Repletion.
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge:

Body weight (BW) = 70 kg

Daily requirement of magnesium (DR) = 10 mg/kg

Serum magnesium level (SR) = 1.5 mg/dL

Target serum magnesium level (T) = 2 mg/dL